While the use of a liquid metal as a heat transfer medium in systems such as the liquid metal fast breeder reactor has proven to be effective, liquid metal leaks in the steam carrying tubes which are contacted by the liquid metal typically require costly inspection operations which may take many days to complete. While gross indications can be obtained to indicate the presence or absence of a leak, conventional external leak monitoring equipment is incapable of identifying the specific tube and a specific location on the tube where a leak exists.